New Delhi: Babies getting their third dose of oral polio vaccine (OPV) will now also be administered an injection with inactivated polio vaccine (IPV), as part of India’s efforts to boost its polio immunization programme. IPV and OPV together can provide additional protection to a child.

India was certified polio-free on 27 March 2014, but the immunization programme continues in the country since two of its neighbours remain polio-endemic and due to the threat of vaccine-derived polio.

In the first phase, the injection will be introduced in six states: Assam, Bihar, Uttar Pradesh, Gujarat, Madhya Pradesh and Punjab.

“The last polio case was reported in India in 2011. But the risk is still there with the virus being active in Pakistan and Afghanistan. Hence, we are introducing IPV for double protection against polio," said Union minister for health and family welfare J.P. Nadda, at an event to launch the vaccine. “By 2016 April, we will switch from trivalent to bivalent vaccine. We have to ensure that core and support systems work, along with a robust cold chain system and improved routine immunization," added Nadda.

Trivalent vaccines protect against three strains of the polio virus while the bivalent variety protects against two. Immunization programmes the world over are switching to the bivalent vaccine since the third strain has been eradicated, and the trivalent vaccine could theoretically re-introduce it.

There are challenges that come with the introduction of the vaccine. IPV is an expensive vaccine and each dose costs around ₹ 120 and unlike OPV, the IPV which is an injectable vaccine can only be given by trained health workers at vaccination sites. There are also issues of vaccine availability which the health ministry is trying to resolve.

“IPV is a key step towards global endgame strategy. It is a tough task to convince a population to continue with OPV after a country is declared polio-free and even harder to introduce IPV on top of that," said Louis George Arsenault, country representative India, Unicef. “A lot of people doubted India could get polio-free, but it happened. We now look forward to a transition from OPV to IPV. If India can do it, so can the world," he added.

IPV is not a new vaccine and was first used in 1955. Thirty countries have already introduced IPV in their national immunization schedule, while 126 countries including India will introduce IPV soon.